Barrier coatings for CIGSS and CdTe cells

Barrier coatings for CIGSS and CdTe thin film solar cells will be critical for achieving reliable and long lived devices. Coatings based on a multilayer polymer/oxide approach developed at PNNL are being investigated as effective encapsulation of thin film solar cells. CIGSS circuits provided by Shell Solar Industries (SSI) and CdTe cells fabricated by the W. S. Sampath and coworkers at Colorado State University (CSU) are being utilized for the study. Barrier coatings involve deposition of a relatively thick polymer layer to establish a smooth surface for subsequent deposition of an oxide layer. Deposition of the first polymer/oxide dyad is followed by one or more additional pairs of polymer/oxide dyads. Very positive results have been obtained for encapsulated CIGSS circuits and CdTe cells subjected to 60°C and 90% relative humidity.